Composite structural components containing thermotropic liquid crystalline polymer reinforcements for optical fiber cables

Abstract

A process for producing an optical fiber cable composite structural component, such as reinforcing members, buffer tubes, filler rods, jackets, and slotted cores, is disclosed. The composite structural components are produced by co-extruding a thermotropic liquid crystalline polymer (TLCP) and a thermoplastic matrix material into the composite structural component so that TLCP reinforcing fibrils are dispersed in the thermoplastic matrix material. The TLCP reinforcing fibrils undergo a high level of process induced orientation, are provided with a high aspect ratio, and small diameters. The composite structural component has a high modulus. The TLCP reinforcing fibrils may be made continuous or discontinuous.

1. A method for producing an optical fiber cable composite structural component, the composite comprising a thermoplastic polymer matrix containing a thermotropic liquid crystalline polymer dispersed therein, the method comprising the steps of:
 providing a thermoplastic polymer matrix melt stream; 
 providing a thermotropic liquid crystalline polymer melt stream; 
 dividing the thermotropic liquid crystalline polymer melt stream into a plurality of thermotropic liquid crystalline melt streams; 
 injecting the plurality of thermotropic liquid crystalline polymer melt streams into the thermoplastic polymer matrix melt stream to form a composite melt stream comprising a thermoplastic polymer matrix melt stream containing a plurality of thermotropic liquid crystalline polymer melt streams dispersed therein; 
 passing said composite melt stream through a static mixer to subdivide and draw down the individual liquid crystalline polymer melt streams; 
 extruding the composite melt stream through a die to form the optical fiber cable composite structural component. 
 
     
     
       2. The method described in  claim 1 , wherein the composite melt stream is cooled, and pelletized, and the resulting cooled, and pelletized material, and the resulting cooled and pelletized material is extruded into the structural component. 
     
     
       3. The method described in  claim 1 , wherein the structural component is extruded through the die at a rate in the range of about 25 to 100 meters per minute in a temperature range of about 222 to 234° C. 
     
     
       4. The method described in  claim 1 , wherein the structural component is extruded through the die at a rate of at least about 50 meters per minute in a temperature range of about 222 to 234° C.